Abstract:
Variability is potentially a powerful probe of several million year
old stars, constraining such varied physics as stellar activity, dust
disk geometry, and accretion dynamics. So far, only periodic
variability, related to stellar activity and rotation, has received
significant attention. We are carrying out a large-scale systematic
survey of periodic, aperiodic, and episodic variability in the North
America Nebula region. With this survey, we will be able to construct a
complete membership list based on variability, infrared, and
spectroscopic properties, determine the rotation period distribution and
compare it to that in other star-forming environments, determine the
distribution of timescales associated with variable accretion, and
determine the distribution of spatial scales associated with
inhomogeneous circumstellar dust. Here we propose a multi-band
photometric monitoring campaign targeting the North America Nebula. The
new observations will extend our survey to cover rapid (few hours to few
days) flux changes, and will provide color information essential to a
thorough understanding of the physics underlying young stellar
variability.